When it comes to commerically available funnels there is a wide variety that fits the majority needs.
I am a minority and have special needs when it comes to funels.
This one fits a version of the water cooling system top up needs on the top of the jar lid between all the cables, hoses, taps, pumps and stands.  Because yes, you need to top up the jar every 20 to 50 hours of pritng, water has a habit to evaporate slowly.
There is a version of hose bracket with funel included to be printed and in that case you do not need this one.

For the price you have one  funel.   You need to buy the M3 nuts and bolts.

Word of advice from experience, PLA will fail in time due to proximity of hot elements like boiling water, steam etc, and some chemicals, but is cheap.

If you intend to use your funel on the hot side of water do not go for PLA, rather nylon, or PPS or similar, if you intend to go corosive elements through it and really hot subsances, I reccomend you go PEKK.